A filling device for filling secondary containers within a primary container. The filling device includes a filling platform that includes a base and filling channels that are in fluid communication with the base. The filling device also includes a retention platform for retaining secondary containers in contact with the filling platform during filling. The filling device, with secondary containers attached thereto, is placed within a primary container and material is supplied to the filling platform in order to fill the secondary containers. When complete, the filling device is removed and the filled secondary containers remain within the primary container.